Support "/" options on Windows, and "/?" for help about args

[DartBot]

<img src="https://avatars.githubusercontent.com/u/46275?v=3" align="left" width="48" height="48"hspace="10"> Comment by munificent

---

Marked this as blocking dart-lang/sdk#7489.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/103167?v=3" align="left" width="48" height="48"hspace="10"> Comment by srawlins

---

I think it would be crazy unexpected if on a non-Windows system, args parsed arguments starting with a / as an option. IE:

my_dart_script --foo=bar /baz

If my_dart_script happens to also have an option "--baz" defined, it should not read "/baz" as an option! I suggest using Platform.isWindows for this feature. This is still a little wonky, however, because then Window folks would still be able to supply options with -- and with /, so the above example is just as confusing, but only for Windows folks.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/46275?v=3" align="left" width="48" height="48"hspace="10"> Comment by munificent

---

Yeah, I don't think we should support any of this on non-Windows platforms. Platform.isWindows is probably the right approach, but note that that's a breaking change for args. Currently, it doesn't import anything except "dart:io" and it can be used outside of the standalone VM.

[nex3]

Uri.base can be used now to determine the operating system without importing dart:io.